1. Field of Invention
The present invention relates to television receivers in general and, more particularly, the invention relates to a method and apparatus for setting the time of day information that is stored in a television receiver clock.
2. Background of the Disclosure
It is anticipated that future television receivers will be able to receive television signals from multiple sources, such as satellite, cable, and terrestrial broadcast. Moreover, such television receivers will be able to accommodate television signals including both analog and digital television formats.
Present analog television formats comprise those promulgated by the National Television Standards Committee (NTSC), Sequential Technique and Memory Storage (SECAM) and Phase Alternation by Line (PAL). Current digital formats comprise those promulgated by Direct Broadcast Satellite (DBS) such as DirectTV, and the digital terrestrial broadcasts such as High Definition Television (HDTV), in accordance with the American Television Standards Committee (ATSC) and the Movie Pictures Expert Group (MPEG) standards.
A problem has been identified in setting an integrated receiver and decoder (IRD) digital clock when multi-format sources are received by a television. Specifically, DBS receivers do not allow the user to set their own time, date, daylight savings time, or time zone information.
Furthermore, each format may, have temporal information transmitted along with the video and audio information. Broadcasts from digital terrestrial sources usually include temporal components, however, the temporal components may differ from channel to channel. For example, a channel for NBC may provide a digital temporal component having a time value of 2:06 p.m., while a channel for ABC may have a temporal component having a value of 2:09 p.m. Moreover, digital broadcasts from satellites may transmit temporal information that differs from the digital terrestrial broadcasts, e.g., 2:07 p.m. Conversely, typical broadcasts from analog terrestrial sources do not include temporal components.
Thus, the clock in the IRD of a television receiver is set by extracting the temporal components from the digitally transmitted television system. As a user changes the source for receiving the television signal, e.g., DBS to analog terrestrial broadcast, the user is prohibited from manually changing the clock time of the television. Therefore, the values of the temporal components in a television signal will subsequently be the time the clock of the television receiver maintains, until another digital broadcast source with temporal information is selected by the user.
A problem arises from the inability of a user to manually set time illustratively, when the user desires to record a specific program on a channel from one source (e.g., CBS broadcasted via an HDTV transmission, at 8:00 p.m.), but the television""s internal clock was previously set by another source (e.g., DBS at 7:55 p.m.). In this instance, a clock in the user""s television is set by the DBS temporal signal, and will display 7:55 p.m. The DBS temporal information is out of synchronization with the HDTV broadcasted temporal signal, lagging by five minutes. Five minutes later, when the clock displays 8:00 p.m., the recorder will begin to record the selected station, CBS. However, the first five minutes of the CBS programming will not be recorded, since the CBS channel time is five minutes faster than the HDTV broadcasted channel.
Additionally, there is a need to prohibit the user from manually setting the clock for a specified interval of time, so as to preclude an unwanted change in time. For example, a child may change the time of the television clock in order to record a program not suitable for child viewing. In this instance, the mere manipulation of the clock settings will allow the child to circumvent parental control.
Therefore, there is a need in the art for a method and apparatus that permit a user to selectively set the clock on their television receiver to adjust for time differences between the multi-formatted sources of television signals, without interfering with the temporal time transmitted by one of the multi-formatted television signals.
The disadvantages heretofore associated with the prior art are overcome by the present invention of a method and apparatus for allowing a user to manually set a clock in a multi-format television receiver capable of receiving a plurality of television signals. The method comprises the steps of selecting a television signal from one of a plurality of television signals and then detecting temporal information in the television signal. Upon detecting such temporal information, components of the temporal information are extracted and used to set at least one clock to count time. Once the clock is set based upon the extracted temporal components, the values of the temporal components prevail over any manually set time, and the user is precluded from manually setting a time value or date value on the clock. The television receiver continues to update the clock based upon the latest periodic temporal information sent with the television signal. The user is permitted to manually set the time on a clock only in an instance where the updated temporal information has not been detected past a specified period of time (e.g., 1-hour).
Additionally, a user may manually set the time zone value or daylight savings time value on the clock at any time. In order to count time based upon the temporal components detected in the television signal, the manual clock settings must match the values of the temporal components. A default device is provided to set the time zone value or daylight savings time value on the clock, in an instance that it is desirable to utilize such temporal information in the television signal.
Thus, a user may manually set the clock in a timely manner without interfering with broadcasted television signal having temporal information. In addition, the user may prohibit other users from manually setting the clock for a specified interval of time, so as to preclude an unwanted change in time (e.g. a child attempting to watch or record a program not suitable for child viewing).